EXR format for skybox?

arqcova , not at the moment - may I ask why you wish to use this specific format in general? Have you found a good source for example?

Quote from arqcova

I had a library for some EXRs, just wanted to try them out without changing them to HDR ( I don't know the real difference between the two)

I see!

About the difference itself, an excerpt from the HDRI Haven site:

"While EXR files are objectively better than the HDR format, being true 32-bits per pixel per channel, the practical difference is insignificant.

Generally 32-bit losslessly compressed EXR files are at least double the size of HDR files, while the difference between them (both the files themselves and the lighting they produce) is impossible to distinguish with the naked eye even when zooming in to potentially worst-case-scenario regions and flicking back and forth between them."

Furthermore, if you have a library of quality EXR files you want to use in Enscape, perhaps simply check out a converter like this one here, or here. Hope that helps!